#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
typedef long long ll;

int main() {
    int N;
    cin >> N;
    vector<double> v(N);
    rep(i, N) cin >> v[i];
    sort(v.begin(), v.end());
    if(N % 2 == 0) {
        cout << (v[N / 2 - 1] + v[N / 2]) / 2 << endl;
    } else {
        cout << v[N / 2] << endl;
    }
}